There are two types of dependents, "Qualifying Children"(QC) and Other ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, student status, a relationship test, support test, and residence test.
The support test is different for each type. The support test, for a QC, is only that the child didn't provide more than half his own support. The support test for a Qualifying Relative is that the taxpayer provided more than half the relative's support.
If he qualifies as your dependent, then you (not him) claims the American Tax Opportunity (education/tuition) Credit.
If he qualifies as a qualifying child dependent, you also get to claim the EITC, if your income is low enough ($66,819 not $160,000*).
*See https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/earned-income-and-earned...
